Sound-transmitting apparatus.



v K C. W. MGGONIGLE.

' SOUND 'rnANsm'T'rmG APPARATUS.

APPLICATION Y"ILIBD YEB.5, 1912.

1,049,253'. Patented Dec. 31, 1912. l

' A A rron'zmsrA t y l'iAirErrr onirica,

i Wl.' M cGoNGLE, orIALGoNA, wilsi1ivewro1v,A Assmnonl To THEGLOBE TELE-f f PHONE comPANY; oF SEATTLE, WASHINGTON, A CORPORATION or WAsHINGToN.

' 'igogtogss.

' To'all pwi it may'convcam: l Y Be it known that 1;.. CHARLES. W .MC-GoN1GLi-:, azcitizen .of the United States, re-

lo'w'ing is a specihcation. 5

' i-ons' is' especially designed for-use witll the receiverof aniordinary.telephone system, o r with a wireless telephone by connectingthe l'f-thewireless systeml' A i The bject of theinvention 1s theperfeqting of {devices of this character whereby the 'transmission ofsound is rendered peculiarly e fect ive..' A The 'inventionis.illustrated by the accom- '-Qpanying drawing, which shows in sectiona sound transmit-ter witlrthe electricalA circuits A therefor showndiagrammatically.'

I The Vreference` numerals 2 and 2'. designate-two diaphiiagn'is"secured 'about their peripheries to vthe `ends of' a hollow -suppc rt.3 there-for. Communicating with the space -within said supportis a horn.4. 'Attachedto .the respective diaphraguis andv exttmdingv 130ax'i'allytherefroniare metallic rods 5 and 5 which areccnneetedby wires aand a.with a sourceof direct current electr-ic supply, asv

c indicatedat- B. Secured to 'said rods ar'e disks v(ii-servingfaselectrodes for the circuit B'meinbers'comprised .of the respective wiresand, rods. Associated with each' of said disks are stationary metalplates l'i' and 7' -wliich serve asl electrodes for circuit. wires I)v'fand b,^ res1v)ecti.vely. The latter are :con- 40, nected in -parallelwith a telephone receiver A"-R,vo'r an -equivalent,jand desirablythroughthe instrunientalityof atransforiner o r an Ainduction coil' T,having aprimary 'winding offre'lativelyf low resistance'.- Thefpl-ates 7 A51-and77 are disposed in spaced relations at opposite sides'of the respectivedisks and are `inclosed in receptacles such-as 8, 8582 andliiaterialyindicat'ed by 9,.' are 'provided belllnt'een the.- .and the'various associated plates.

" y In operation, the' 'iindulator y movements of.' the gdiaphragmsgenerated by sound' i; resulting 'in the granular 0 c g. ing varying4amounts of sidlng at Algona; 1 n the county. of King'and'} :15j State.of Washingtoin' have.A inventedcertain tiode's Tand-17..=tpnlsestthnsltransmitted.through the eleei8'*.`z Granulesoffcarbomoran"equivalent- S-pecitcation'of Letters lateiiti Patentedpiilication filed I EeliriiaI'y 5,l 1 912. i

site sidesof the movable electrodesii'itl'ordflow of electric currentsor impulsev `the ilG-riiiall)Y .incomplete local c" to'ftlie circuitconnections b, Z4v 'of th The series of'el'ecl trodesare'of an:alternatingr e .icterand arejthus applied'througli the medium of theinduction coils T to the circuit wires of the receiver R.

trod 6 which are' connected therewith arecaused to approach theelectrodesv T wherev` 9- is lessened between the referred to electrodeswith a'proportioiial increase in tht` resistance afforded by the saidmedium with respect to electrodes Gand T. Consequently.

as the'niovable electrodes (3 are alternatelj:

brought into proximity of the stationary electrodes. it is evident thatalternating eur rents are produced in the circuit wiresl L. lf.'ll'heirthe electrodes t3- are brought into neutral positionswvitlrrespect te the other electrodes, as would be the condition whenthe diaphragins are uninluenced 'b v. sound waves,A the wires bpb wouldbe short-eircuited between the various movable eleetrodes and all ot'the otlieis and lienee be ineffective at the receiver.

The number olf groups of transmitting! elements `composed of anelectrode (i inter# posed between the granular 4matter and the adjacentAfixed electrodes may be varied to siutthe service or according-to theamper` ageV or current supplied.'

By such devices a relativel) strong-cin'- rent, asGOO volts. forexample. may be'exnployed and that, too, from a circuit which isutilized for supplyingv power directly to electric motors and withoutinjuring the certainty and definition' of `the sounds. transmitted theinstrument.l

*What I'clam as my invention.. is-

= V1'. In apparatus of the class dessrihed. the combination -of twovibratile diapliragius.

pairs-of iioii-iiim'alile 'electrt-des disposed :it

stitutingr the terminals ofthe primary wind- Aingof an induction coil. amovable elet-trede -More particularly, when the,A c diaphragnis arepressed outwardly the elecinstrument withvthesending appliances ofresista-nce: tio the sfo A .752 upon the resistancetitlorded b v thenie\'liu.in

positioned intermediate die-aforesaid eleetrodes ofeacli pail-a granularmedium disposed in the'spu'ces between tlieinm'able elec- -trodes andthe non-movable electrodes, posi-A tive connections between the movableelectrodes and the respective diaphra and the complementary circuitwires olzs direct current electr-ic 'supply connected with ,therespective movable electrodes. Y

2. In apparatus of the class described, the combinationof a pair ofspaced diaphragms' adapted to be vibrated in opposite directionswheninfluenced by sound waves2 resistance chambers disposed at oppositesides of the aforesaid pair of Vdiaphragms, a non-mov` able electrode4ai: each end of t-helres ective resistance chambers, -a primary wind)aninduction coil,` one of the terminalsv o'f said Winding beingconnected to the electrodes adjacent. to the diaphragms at one.A

ing ofl vside of the lat-terand alsowlth the electrodes A Jan., 1912.

remote'rom the diaphragm's at the opposite `Side,'the other terminal ofsaid winding being similarly connected with the remaining of saidelectrodes, a movable electrode inter-v posed between the two electrodesofeach of the resistance chambers, rods connecting thesite lsides of thepair'of diaphragms.

'- Signed at Seattle, Wash., this 30th Aday of CHARLES W. .MGGONIGLE

